Prognostic significance of spleen shear wave elastography and dispersion in patients with heart failure: the crucial role of cardio-splenic axis.

ABSTRACT

INTRODUCTION: The interaction between the heart and spleen plays a crucial role among cardiac and multiple organ networks, particularly in heart failure (HF). Ultrasound shear wave imaging is a non-invasive technology capable of quantifying tissue quality, but its significance in the spleen in patients with HF is poorly understood. METHODS AND RESULTS: This prospective observational study enrolled hospitalized 232 patients with HF undergoing abdominal ultrasonography. We used shear wave elastography (SWE) to assess spleen tissue elasticity and shear wave dispersion (SWD) to assess spleen tissue viscosity. Clinical, echocardiography, right heart catheterization, and outcome data were collected. Spleen SWE was negatively correlated with right ventricular fractional area change (R = - 0.180, P = 0.039), but not with right-sided pressure or congestion indices. When patients were divided into three groups based on tertile values of splenic parameters, Kaplan-Meier analysis demonstrated that patients with the highest spleen SWE and SWD had lower event-free survival rates from cardiac deaths and decompensated HF over a median 494-days follow-up period (P < 0.0001 and P < 0.0001, respectively). In a multivariable Cox proportional hazard model, both spleen SWE and SWD were independently associated with increased risks of adverse cardiac events (hazard ratio, 4.974 and 1.384; P = 0.003 and P < 0.0001). Mechanistically, we evaluated mRNA expressions of CD36, a monocyte/macrophage-associated molecule, in peripheral leukocytes, and found that enhanced spleen stiffness was associated with the upregulation of CD36 expressions. CONCLUSION: Share wave imaging of the spleen is useful for stratifying the prognosis of HF patients and may suggest a role of the cardio-splenic axis in HF pathogenies.